How do I tell when TTree::Draw() is really done?

ROOT
1

I am using win32gdk v 3.10/02 (so far it seems to work great!) I have an application that calls, eg, TTree::Draw(“y:x”) in response to button clicks. These often take significant time to get drawn. I want to provide feedback to the user with a message in the status bar, e.g.pStatus->SetText("Preparing display, please wait..."); pTree->Draw(...); pStatus->SetText("Idle"); The problem is, the statusbar text turns to “Idle” long before the canvas get updated. Is there a way to get notification when the canvas us finished being updated? Thanks.

Ed Oltman

2

Hi Ed,

I could easily add the emission of a Signal when TTree::Draw has finished.
Would you be happy with that solution?

Rene

3

Rene,
Yes, that would work for me. I also have the same problem with TH2::Draw(“colz”) - there are probably other Draw()'s that can be time consuming as well… Thank you.
Ed

4

Hi Ed,

Thinking a bit more to the problem, it looks more appropriate to emit a signal when
the pad starts the Update process.

Rene

5

Hi Rene,
Did you ever add a signal when the pad starts the update process? I assume thats after all the cpu intensive stuff is done… Thanks
Ed